Belongs within: Ichneumoninae.
Big-cheeked mummy-makers
Published 13 February 2026
The ichneumons are well recognised as one of the most diverse families of wasps in the modern world, and there has mostly been little debate over what is and is not an ichneumon. The question of subdividing the ichneumons, however, is a different matter.
The Alomyini are currently recognised as a small tribe of medium- to large-sized ichneumons found in the Palaearctic realm. The majority of species are included in the single genus Alomya; a second small genus Megalomya is recognised from southern China. Where their natural history is known, Alomya species develop as parasites of the caterpillars of Hepialus swift moths. In the process of development, the Alomya larva ends up turning its host into a desiccated mummy before emerging as an adult.
Alomyins have commonly been included in the large subfamily Ichneumoninae though many authors have instead considered them their own subfamily Alomyinae. For those considering them ichneumonines, there has also been a long-running question whether they are distinct from another ichneumonine tribe, the Phaeogenini (if the two are combined, ‘Alomyini’ remains the name for the broader construct). However, alomyines may be distinguished from other ichneumonines by the absence of the trochantellus, an extra short leg segment at the base of the femur. They also exhibit a distinct head structure, in which females have the genae and postgenae (what might be thought of as the wasp’s ‘cheeks’) meet behind so the mouthparts emerge from a closed ring-shaped opening. In males, the genae are not entirely closed, but they are further extended behind than in other ichneumonines (Tereshkin 2009).
A recent molecular phylogenetic study by Santos et al. (2021) supported the distinction of Alomyini from Phaeogenini, placing the Alomyini as the basalmost clade within the Ichneumoninae, and the Phaeogenini as the next to diverge. Pseudalomya, another small genus intermediate in appearance between Alomyini and Phaeogenini (it has closed genae like an alomyin, but a standard ichneumonine trochantellus), was placed by this phylogeny firmly among the Phaeogenini. Whether alomyins represent part of the ichneumonines, or their own subfamily, is therefore just a question of where one calibrates the boundaries.
Systematics of Alomyini
AlomyiniNI11
|--MegalomyaG84
|--Lusiuxta floreni Diller 2006NI11
|--AlomyaG84
| |--A. debellatorR26
| `--A. ovator [=Ichneumon (Alomya) ovator]G20
|--Diadromus Wesmael 1845NI11, G84 [incl. Thyraeella Holmgren 1890G84]
| |--*D. troglodytes [=Ichneumon troglodytes]G84
| `--D. collaris (Gravenhorst 1829)NI11 [=Ishnus collarisNI11, *Thyraeella collarisG84]
`--TycherusNI11
|--T. cacumencultor Diller 2006NI11
`--T. sabahensis Diller 2006NI11
*Type species of generic name indicated
References
[G84] Gauld, I. D. 1984. An Introduction to the Ichneumonidae of Australia. British Museum (Natural History).
[G20] Goldfuss, G. A. 1820. Handbuch der Naturgeschichte vol. 3. Handbuch der Zoologie pt 1. Johann Leonhard Schrag: Nürnberg.
[NI11] Norhafiza, A. F., & A. B. Idris. 2011. A catalogue of Ichneumoninae (Hymenoptera: Ichneumonidae) from Malaysia. Serangga 16 (1): 29–50.
[R26] Risso, A. 1826. Histoire naturelle des principales productions de l’Europe méridionale et particulièrement de celles des environs de Nice et des Alpes maritimes vol. 5. F.-G. Levrault: Paris.
Santos, B. F., D. B. Wahl, P. Rousse, A. M. R. Bennett, R. Kula & S. G. Brady. 2021. Phylogenomics of Ichneumoninae (Hymenoptera, Ichneumonidae) reveals pervasive morphological convergence and the shortcomings of previous classifications. Systematic Entomology 46: 704–724.
Tereshkin, A. M. 2009. Illustrated key to the tribes of subfamilia Ichneumoninae and genera of the tribe Platylabini of world fauna (Hymenoptera, Ichneumonidae). Linzer Biologische Beiträge 41 (2): 1317–1608.